It has been recognized that the shelf-life of the medications can be increased dramatically if the drug is stored as a dry medication. In addition, it is often that these medications are deployed in emergency situations where self-administration is preferred. In such emergency situations, the various actuation and mixing steps need to be performed in an intuitive manner such that they can be performed reliably in emergency situations with minimal complexity. For this reason it would be useful to have an easy-to-use auto-injector or a syringe-type device that automates the drug preparation process while also providing a platform which requires minimal user training and opportunity for user failure or dosing inaccuracy.
The invention here describes an interface whereby a single user input, involving removal of the cap, sets off a cascade of mechanical functions that initiates mixing, signals the completion of mixing, and places the device into an injection-ready state.